This section provides a guideline on how to integrate VIOSO multi-projector and multi-client calibrations into Unreal Engine.

Unreal Engine uses nDisplay for distributing and synchronizing content over multiple displays and servers. It can integrate VIOSO’s calibration data through the MPCDI or .VWF data formats.

Please note that VIOSO 6 SIM or VIOSO Anyblend VR&SIM v5.1.7+ is required to generate suitable MPCDI/VWF files!

Workflow in the steps below:

1. In VIOSO software

Perform a camera based 3D calibration with VIOSO 6 SIM or Anyblend VR&SIM  (version  5.1.7 or later). You can use either: Free mode or project mode (3D mapping)

After a successful 3D calibration of your displays, export your mapping in VWF or VESA MPCDI v2 formats. The difference between both formats is explained in section 3. Tips & Notes.

From the menu bar, go to File > Export Mapping:

• Select your compound display.
• Select the VWF or VESA MPCDI v2 format.
• Make sure the 3D box is checked, and for mpcdi set Blend Bit depth to Grey8 or Grey16
  
• Choose a file name and path.
• Click on Export.

– For mpcdi: the export will be a folder containing an XML document along with a set of PFM files for geometry and their respective blending masks as PNGs.

– For vwf: the export will be a VIOSO format file containing several mappings or a set of files containing one mapping each. You can preview vwf files in Windows with a tool installed by default with the VIOSO software: “C:\Program Files\VIOSO6\Shared tools\VIOSO_CalibAssign64.exe”

2. In Unreal Engine

2.1 versions 4.27.x – 5

a. Workflow

The integration of the calibration files is done through the Projection Policy of the nDisplay viewport.

First you need to setup your project and have it up and running on all clusters and displays. Then, switch the projection policy of each target viewport to type= VIOSO or MPCDI. You can do this either through the user interface 3D config Editor or by editing the configuration files (.ndisplay), (.cfg).

The configuration parameters are detailed in the table below:

b. Example Configurations

Find here example files for VIOSO calibrations (v4.27 & v5)

2.2 versions 4.24 – 4.26

a. Workflow

First, follow the Quick Start Guide to get nDisplay up and running.

Step 1 – Set up Your Project for nDisplay

Step 2 – Set up the Configuration File

This is where the VIOSO calibration is integrated.

After you have configured your clusters, windows, and viewports according to the config file reference, you need to set your projection type to “mpcdi” and specify your .pfm and blending masks paths for each viewport in the format below:

  [projection] id=proj_pfm_1 type="mpcdi" pfm= "..\..pfm" alpha="..\..png"

Optionally, you can add these parameters to the above line:

Step 3 – Package and Deploy

Step 4 – Launch all Cluster Nodes

b. Example Configurations

Find here example files for VIOSO calibrations (v4.24-.26)

3. Tips & Notes

• Make sure all paths and file names of your configuration contain no spaces.
• Carefully verify the syntax of your .cfg /.nDisplay file. A single typo may cause the application to crash at start-up.
• Check the log files generated in [YourBuildPath]\nDisplay\Saved\Logs to monitor the events and errors of the application.
• Make sure that the Windows account you intend to use on the master computer has administrative rights on all computers you will use in the nDisplay network.
• Make sure that all computers you want to use in the nDisplay network can receive TCP/IP communications over ports 41000, 41001, 41002, and 41003.
  (You can use different ports instead; see Changing nDisplay Communication Ports)
• Eyepoint Position: you can define the initial eyepoint position relative to your 3D model center by adding an “origin” param in the projection definition (MPCDI or VIOSO) and then defining its coordinates in a [scene node]. This origin is relative to the center of the 3D model used for the calibration and expressed in UE coordinate system.
• MPCDI vs VWF  formats:
  VIOSO also has a native integration into nDisplay (UE v4.26+), allowing you to use the (.vwf) export format instead of MPCDI in the projection policy. This table summarizes the main differences and advantages of choosing between the two formats: